Messed up jailbreak/restore iPhone

I just finished registering myself on this website. I really need some help with my iPhone.
I tried jailbreaking it today and seriously messed up.
I went onto a website and downloaded the file for 3Gs. The problem is that I don't know if my iPhone is a 3G or a 3Gs. It has 16GB of space, like only the 3Gs do, but it can only take photos, doesn't have the compass or the voice control so I'm not sure which one it is and I have searched and searched on google for a way to tell me how I can find out which one it is, but no luck.
The reason I dont know if because I didn't buy it, my father found it on the floor of a bed store - it probably fell out of the previous owners pocket when he was trying out beds - so he thought, if I give it to the people who work at the shop, they're probably going to keep it so I'll give it to my daughter who doesn't have a phone. I know it's not right to keep something that isn't yours but I didnt steal it and I'm sure anyone would keep a 600 or 500 pound phone if they found one lying on the floor.
Anyway, I thought it was a 3Gs, so I downloaded the 3Gs file. It didnt match up with the instructions but I thought that wasn't a problem. In the end, redsn0w would stop working so I gave up. I then tried downloading the 3G one. Now this one corresponded to the instructions so I thought I was on the right path again. I did the hold the off button 3 seconds, then the home button more seconds and then just the home button for even longer. Didn't work the first 2 or 3 times. Then once iTunes opened up and said I should restore it. Ok, fine. I thought I could restore it, clean it up and then jailbreak it properly. Left iTunes downloading and then when it finished, tried restoring it but it said that my sim card was not accepted. Now I think I should say that my dad found it in England, where he lives, but I live in Portugal, so I have a Portuguese sim card so of course, it wasn't going to accept my sim card.
Now I've been looking on the internet for a way to format, clean or restore my iPhone without having to use iTunes or going into the menu or general, because I can't even chose it because all I get when i turn it on is an icon of iTunes, a usb pointing at it, an option for emergancy calls and a text box saying that my sim card is blocked.
I really need some help =( I usually go and look for help on google and I usually find it but this time I really can't find anything or anyone that has ever had this problem. I'm sorry that the text is long but I wanted to give all the info for anyone willing to help me.
Thanks in advance.

The reason I dont know if because I didn't buy it, my father found it on the floor of a bed store - it probably fell out of the previous owners pocket when he was trying out beds - so he thought, if I give it to the people who work at the shop, they're probably going to keep it so I'll give it to my daughter who doesn't have a phone. I know it's not right to keep something that isn't yours but I didnt steal it and I'm sure anyone would keep a 600 or 500 pound phone if they found one lying on the floor.

First off you probably have a 3G (no compass, or video option). The easiest way to tell is to look at the back: If the iPhone writing at the bottom is chrome color kind of like the Apple logo it is a 3GS - the 3G's writing is a darker almost gray color.

What are you running for a computer anyway? Mac or PC?

Your best bet is to try and restore it to 3.0 and go from there: Download the 3G 3.0 firmware and restore to it - Do not do a factory restore through iTunes or you will lose the ability to unlock it (if you haven't lost it already).

Hey, thanks DrewGzy.
Yeah the writing on the back is very dark, so I assume its a 3G. Thing that still puzzles me is that it has 16GB of memory. Isn't that only available for 3Gs? I went on the Apple website and you could only buy 3G's with 8GB.
I have an iMac with bootcamp and I used Windows Vista to jailbreak it.
And yes, unfortunately it has gone back to factory settings using iTunes yes =( any help on what I can do now?
For brendanm:
1st - Yes, I am a girl.
2nd - No I did not buy it, my dad found it.
3rd - If you want to learn how to read and help other people, I think you should stop drinking and getting hangovers in my opinion! XD

Hey, thanks DrewGzy.
Yeah the writing on the back is very dark, so I assume its a 3G. Thing that still puzzles me is that it has 16GB of memory. Isn't that only available for 3Gs? I went on the Apple website and you could only buy 3G's with 8GB.
I have an iMac with bootcamp and I used Windows Vista to jailbreak it.
And yes, unfortunately it has gone back to factory settings using iTunes yes =( any help on what I can do now?
For brendanm:
1st - Yes, I am a girl.
2nd - No I did not buy it, my dad found it.
3rd - If you want to learn how to read and help other people, I think you should stop drinking and getting hangovers in my opinion! XD

Click to expand...

the previous owner bought it before.... before the 3gs came out there was a 16gb iphone 3g and an 8gb.